8330172: G1: Consolidate update_bot_for_block and update_bot_for_obj …

…in HeapRegion

Reviewed-by: ayang, tschatzl

src/hotspot/share/gc/g1/g1HeapRegion.cpp

@@ -724,10 +724,6 @@ void HeapRegion::mangle_unused_area() {
 }
 #endif
 
-void HeapRegion::update_bot_for_block(HeapWord* start, HeapWord* end) {
-  _bot->update_for_block(start, end);
-}
-
 void HeapRegion::object_iterate(ObjectClosure* blk) {
   HeapWord* p = bottom();
   while (p < top()) {
@@ -741,7 +737,7 @@ void HeapRegion::object_iterate(ObjectClosure* blk) {
 void HeapRegion::fill_with_dummy_object(HeapWord* address, size_t word_size, bool zap) {
   // Keep the BOT in sync for old generation regions.
   if (is_old()) {
-    update_bot_for_obj(address, word_size);
+    update_bot_for_block(address, address + word_size);
   }
   // Fill in the object.
   CollectedHeap::fill_with_object(address, word_size, zap);

src/hotspot/share/gc/g1/g1HeapRegion.hpp

@@ -167,12 +167,9 @@ class HeapRegion : public CHeapObj<mtGC> {
   inline HeapWord* allocate(size_t word_size);
   inline HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_size);
 
-  // Update BOT if this obj is the first entering a new card (i.e. crossing the card boundary).
-  inline void update_bot_for_obj(HeapWord* obj_start, size_t obj_size);
-
   // Full GC support methods.
 
-  void update_bot_for_block(HeapWord* start, HeapWord* end);
+  inline void update_bot_for_block(HeapWord* start, HeapWord* end);
 
   void prepare_for_full_gc();
   // Update heap region that has been compacted to be consistent after Full GC.

src/hotspot/share/gc/g1/g1HeapRegion.inline.hpp

@@ -253,17 +253,13 @@ inline void HeapRegion::update_bot() {
   assert(next_addr == top(), "Should stop the scan at the limit.");
 }
 
-inline void HeapRegion::update_bot_for_obj(HeapWord* obj_start, size_t obj_size) {
-  assert(is_old(), "should only do BOT updates for old regions");
-
-  HeapWord* obj_end = obj_start + obj_size;
-
-  assert(is_in(obj_start), "obj_start must be in this region: " HR_FORMAT
-         " obj_start " PTR_FORMAT " obj_end " PTR_FORMAT,
+inline void HeapRegion::update_bot_for_block(HeapWord* start, HeapWord* end) {
+  assert(is_in(start), "The start address must be in this region: " HR_FORMAT
+         " start " PTR_FORMAT " end " PTR_FORMAT,
          HR_FORMAT_PARAMS(this),
-         p2i(obj_start), p2i(obj_end));
+         p2i(start), p2i(end));
 
-  _bot->update_for_block(obj_start, obj_end);
+  _bot->update_for_block(start, end);
 }
 
 inline HeapWord* HeapRegion::parsable_bottom() const {

src/hotspot/share/gc/g1/g1ParScanThreadState.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -444,7 +444,7 @@ void G1ParScanThreadState::undo_allocation(G1HeapRegionAttr dest_attr,
 void G1ParScanThreadState::update_bot_after_copying(oop obj, size_t word_sz) {
   HeapWord* obj_start = cast_from_oop<HeapWord*>(obj);
   HeapRegion* region = _g1h->heap_region_containing(obj_start);
-  region->update_bot_for_obj(obj_start, word_sz);
+  region->update_bot_for_block(obj_start, obj_start + word_sz);
 }
 
 // Private inline function, for direct internal use and providing the